[docs-only] Replace the legacy Extensions with Services (#5518)

* Replace the legacy Extensions with Services

* Update docs/ocis/_index.md

Co-authored-by: Michael Barz <mbarz@owncloud.com>

---------

Co-authored-by: Michael Barz <mbarz@owncloud.com>

docs/services/settings/_index.md

@@ -21,13 +21,13 @@ graph TD
     sdk --- sdks{ocis-settings<br>available?}
     sdks ---|"yes"| os
     sdks ---|"no"| defaults[Use set of<br>default values]
-    oa[oCIS extensions<br>e.g. ocis-accounts] ---|"saveSettingsBundle(bundle)"| os
+    oa[oCIS services<br>e.g. ocis-accounts] ---|"saveSettingsBundle(bundle)"| os
 {{< /mermaid >}}
 
 The diagram shows how the settings service integrates into oCIS:
 
 **Settings management:**
-- oCIS extensions can register *settings bundles* with the ocis-settings service.
+- oCIS services can register *settings bundles* with the ocis-settings service.
 
 **Settings usage:**
 - Extensions can query ocis-settings for *settings values* of a user.

docs/services/settings/bundles.md

@@ -9,7 +9,7 @@ geekdocFilePath: bundles.md
 
 A **Settings Bundle** is a collection of settings, uniquely identified by the key of the
 extension registering the bundle and the key of the bundle itself. Its purpose is to let
-oCIS extensions define settings and make them available to users. They are dynamically
+oCIS services define settings and make them available to users. They are dynamically
 rendered into forms, available in the frontend.
 
 As of now we support five different types of settings:

docs/services/settings/glossary.md

@@ -37,4 +37,4 @@ In the context of this extension and oCIS in general, we are using the following
 
 - Manifestation of a setting for a specific user
 - E.g. used for customization (at runtime) in `ocis-web`
-- Can be queried and modified by other oCIS extensions
+- Can be queried and modified by other oCIS services